1. Field of the Invention
The present invention relates to a mobile electronic equipment, and more particularly, to an mobile electronic equipment such as a folding mobile electronic equipment and the like having a track ball acting as a pointing device for executing manipulations of moving a cursor displayed on a display unit and scrolling a screen on the display unit.
2. Description of the Related Art
In mobile electronic equipment such as a mobile phone and the like, operability is one of the important technical factors. Although pointing devices such as a four-way key, a rotary (jog) key, and the like are used to execute manipulations of, for example, moving a cursor displayed on a display unit and scrolling a screen, a pointing device using a track ball is conventionally known as an example of the pointing devices (for example, refer to Japanese Patent Application Laid-Open (JP-A) Nos. 10-254617 and 2003-29896).
The conventional mobile electronic equipment disclosed in JP-A No. 10-254617 includes a track ball disposed to a main body, and the track ball acts as a coordinate input unit. The track ball permits a coordinate to be input on a display unit as well as can be rotated from two directions, that is, from an upper surface and a lower surface, and respective rotating manipulations can be detected.
The conventional mobile electronic equipment disclosed in JP-A No. 2003-29896 is a mobile terminal including a track ball manipulation means. In the mobile terminal, the information displayed on a display screen is selected or moved by rotating a track ball, and the mobile terminal includes a track ball, a track ball rotating speed detection means, and a display control means which switches an operation for selecting or moving the information on the display screen when a track ball rotating speed is faster than a predetermined threshold value.
However, when the conventional mobile electronic equipment disclosed in JP-A No. 10-254617 is applied to a folding type electronic equipment in which a lower cabinet is pivotably coupled with an upper cabinet at one side ends thereof through a hinge portion and which is used in the opened state, in which the inside surfaces of the lower and upper cabinets are separated from each other, or in the closed state, in which the inside surfaces thereof are disposed in close proximity to each other, the track ball cannot be manipulated unless the mobile electronic equipment is placed in the opened state because the track ball is disposed at a central portion of the lower cabinet. Accordingly, since the conventional mobile electronic equipment disclosed in JP-A No. 10-254617 requires a user action of placing the equipment in the opened state, the equipment is disadvantageous in operability.
The conventional mobile electronic equipment disclosed in JP-A No. 2003-29896 includes the track ball whose upper portion is exposed at the central portion of a main body. Therefore, when the electronic equipment is applied to a folding type electronic equipment, a job for placing the equipment in an opened state is required likewise the mobile electronic equipment disclosed in JP-A No. 10-254617. Further, since the upper portion of the track ball is exposed from the surface of the cabinet, it is impossible to manipulate the track ball by simultaneously holding the upper portion and the lower portion thereof from the front surface and a back surface of the cabinet. Thus, the mobile electronic equipment also has a drawback in operability.